1. Field of the Invention
The present invention is directed to an anti-vibration, brush cutting attachment. More specifically, the attachment is a reciprocating cutter for mounting on the front of a vehicle, such as a tractor or riding lawn mower. The reciprocating cutter removes high grass and brush prior to mowing or traversing the area in front of the vehicle, without causing excessive vibrations to the vehicle or the attachment.
2. Description of the Prior Art
One common type of cutting attachment for lawn tractors, riding lawn mowers, and other vehicles is a sickle bar. Sickle bars can also be formed as stand-alone devices (such as electric hedge trimmers or sickle type lawn mowers) and include two sets of cutting teeth disposed adjacent and abutting one another. As one or both sets of teeth are moved relative to one another in a reciprocating motion, brush, grass and debris located between adjacent teeth are severed. Several types of sickle bars are disclosed in the following U.S. Patents. What is lacking in these references and the prior art as a whole, is a reciprocating sickle bar having two sets of oppositely and continuously driven cutting teeth. This feature of the present invention reduces vibration by balancing oppositely driven masses.
A reciprocating tedder attachment for power mower sickle bars is taught in U.S. Pat. No. 2,448,078, issued on Aug. 31, 1948 to Brown. While the sickle bars shown in this reference are similar in basic operation to the reciprocating cutter of the present invention, the main thrust of this invention involves removal of the cut brush, and the issue of anti-vibration is not discussed. Furthermore, the sickle bars of Brown are not an attachment, but a permanent part of a power mower.
In U.S. Pat. No. 2,680,340, issued on Jun. 8, 1954 to Pazandak, a sickle head mechanism with support mounting is disclosed. This sickle head also operates in a similar fashion to the present invention and is designed to reduce vibrations by yieldably mounting non-reciprocating parts of the sickle head. In this manner, the vibrations of the sickle knife are offset, by the opposite vibrations of the cutter bar and other non-reciprocating parts. While this construction may reduce the overall vibrations transmitted from the sickle head to the handles of the mower, there is no discussion of oppositely driving mower components to thereby cancel the vibration, as in the present invention.
U.S. Pat. No. 5,157,906, issued to Abrahamson on Oct. 27, 1992 shows a divided sickle bar arrangement wherein separate half-sickle portions are individually driven in opposition by belts. This arrangement differs significantly from the positive central crankshaft drive of the instant invention.
An impact actuated mowing machine is described in is U.S. Pat. Nos. 3,657,868, and which issued on Apr. 25, 1972 to Cousino. Two cutting plates are driven in opposite directions against the force of a resilient element. The front edge of each of the cutting plates includes a plurality of cutting teeth that are superimposed over one another in the rest position. Two impact rollers simultaneously drive the cutting plates in opposite directions, thereby reducing vibrations using a cancellation effect. This design uses oppositely moving masses to cancel vibrations, however, it requires two driving sources (the impact rollers), and due to the non-continuous nature of the motion, inherently produces greater vibration than the present invention, wherein only a single driving source (crankshaft) is used, and the oppositely moving parts are continuously driven in opposite directions.
In U.S. Pat. No. 4,107,906, issued on Aug. 22, 1978 to Cousino, another type of impact actuated lawn mower is disclosed. In this impact mower, however, the cutting teeth are not driven simultaneously in opposite directions. The subject of vibration reduction is not discussed or taught in this patent.
None of the above references and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.